Method of making a synthetic alkylaryl compound

ABSTRACT

A process for alkylating an aromatic compound comprising reacting (a) a first amount of at least one aromatic compound with a first amount of a mixture of olefins having from about 8 to about 100 carbon atoms, in the presence of a strong acid catalyst; and reacting the product of (a) with an additional amount of at least one aromatic compound and an additional amount of a strong acid catalyst, and optionally, with an additional amount of a mixture of olefins selected from olefins having from about 8 to about 100 carbon atoms, wherein the resulting product comprises at least about 80 weight percent of a 1,2,4 tri-alkylsubstituted aromatic compound.

FIELD OF THE INVENTION

The present invention is directed to a method of making an alkylatedaromatic (i.e., alkylaryl) compound by reacting an aromatic compoundwith a mixture of olefins selected from olefins having from about 8 toabout 100 carbon atoms in the presence of a strong acid catalyst,whereby the reaction takes place in two reactors in series. Thealkylated aromatic compound may be used as an enhanced oil recoveryalkylate.

BACKGROUND OF THE INVENTION

It is well known to catalyze the alkylation of aromatics with a varietyof Lewis or Bronsted acid catalysts. Typical commercial catalystsinclude phosphoric acid/kieselguhr, aluminum halides, boron trifluoride,antimony chloride, stannic chloride, zinc chloride, onium poly(hydrogenfluoride), and hydrogen fluoride. Alkylation with lower molecular weightolefins, such as propylene, can be carried out in the liquid or vaporphase. For alkylations with higher olefins, such as C₁₆₊ olefins, thealkylations are done in the liquid phase, often in the presence ofhydrogen fluoride. Alkylation of benzene with higher olefins may bedifficult, and typically requires hydrogen fluoride treatment. Such aprocess is disclosed by Himes in U.S. Pat. No. 4,503,277, entitled “HFRegeneration in Aromatic Hydrocarbon Alkylation Process,” which ishereby incorporated by reference for all purposes.

DESCRIPTION OF THE RELATED ART

Mikulicz et al., U.S. Pat. No. 4,225,737, discloses a process for thealkylation of an aromatic hydrocarbon with an olefin-acting alkylatingagent. The aromatic hydrocarbon is commingled with a first portion ofsaid alkylating agent in a first alkylation reaction zone at alkylationreaction conditions in contact with a hydrofluoric acid catalyst.

Boney, U.S. Pat. No. 3,953,538 discloses an alkylation process in whicha stream of an olefinic material is mixed with an acid stream andpolymerized to cause formation of a polymeric diluent for the highstrength acid which is initially charged to the alkylation process.

Mehlberg et al., U.S. Pat. No. 5,750,818 discloses a process for theliquid phase alkylation in an alkylation reactor of a hydrocarbonsubstrate with an olefinic alkylating agent in the presence of an acidalkylation catalyst at least one hydrocarbon having a lower boilingpoint than the hydrocarbon substrate and with a substantialstoichiometric excess of the hydrocarbon substrate over the alkylatingagent to form a liquid product mixture.

King et al., U.S. Pat. No. 6,551,967 discloses a low overbased alkalineearth metal alkylaryl sulfonate having a Total Base Number of from about2 to about 30, a dialkylate content of 0% to about 25% and amonoalkylate content of about 75% to about 90% or more, wherein thealkylaryl moiety is alkyltoluene or alkylbenzene in which the alkylgroup is a C₁₅-C₂₁ branched chain alkyl group derived from a propyleneoligomer are useful as lubricating oil additives.

LeCoent, U.S. Pat. No. 6,054,419 discloses a mixture of alkyl arylsulfonates of superalkalinized alkaline earth metals comprising (a) 50to 85% by weight of a mono alkyl phenyl sulfonate with a C14 to C40linear chain wherein the molar proportion of phenyl sulfonatesubstituent in position 1 or position 2 is between 0 and 13% and (b0 15to 50% by weight of a heavy alkyl aryl sulfonate, wherein the arylradical is phenyl or not, and the alkyl chains are either two linearalkyl chains with a total number of carbon atoms of 16 to 40, or one ora plurality of branched alkyl chains with on average a total number ofcarbon atoms of 15 to 48.

Malloy et al., U.S. Pat. No. 4,536,301 discloses a surfactant slug usedto recover residual oil in subterranean reservoirs. The slug comprises amixture of (1) from about 1 to about 10% of a sulfonate of a mixture ofmono- and dialkyl-substituted aromatic hydrocarbon which has beenobtained by the alkylation of an aromatic hydrocarbon with an olefinichydrocarbon in the presence of a hydrogen fluoride catalyst; (2) a loweralkyl alcohol which possesses from about 3 to about 6 carbon atoms; and(3) a nonionic cosurfactant comprising an ethoxylated n-alcohol whichpossesses from about 12 to about 15 carbon atoms.

SUMMARY OF THE INVENTION

In its broadest embodiment, the present invention is directed to aprocess for alkylating an aromatic compound comprising

-   -   (a) reacting a first amount of at least one aromatic compound        with a first amount of a mixture of olefins selected from        olefins having from about 8 to about 100 carbon atoms, in the        presence of a strong acid catalyst;    -   (b) reacting the product of (a) with an additional amount of at        least one aromatic compound and an additional amount of strong        acid catalyst and, optionally, with an additional amount of a        mixture of olefins selected from olefins having from about 8 to        about 100 carbon atoms, wherein the resulting product comprises        at least about 80 weight percent of a 1,2,4 tri-alkylsubstituted        aromatic compound.

Accordingly, the present invention relates to a process for alkylatingan aromatic compound.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 discloses the alkylation process employed in the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are herein described indetail. It should be understood, however, that the description herein ofspecific embodiments is not intended to limit the invention to theparticular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

Definitions

Olefins—The term “olefins” refers to a class of unsaturated aliphatichydrocarbons having one or more carbon-carbon double bonds, obtained bya number of processes. Those containing one double bond are calledmono-alkenes, and those with two double bonds are called dienes,alkyldienes, or diolefins. Alpha olefins are particularly reactivebecause the double bond is between the first and second carbons.Examples are 1-octene and 1-octadecene, which are used as the startingpoint for medium-biodegradable surfactants. Linear and branched olefinsare also included in the definition of olefins.

Linear Olefins—The term “linear olefins,” which include normal alphaolefins and linear alpha olefins, refers to olefins which are straightchain, non-branched hydrocarbons with at least one carbon-carbon doublebond present in the chain.

Double-Bond Isomerized Linear Olefins—The term “double-bond isomerizedlinear olefins” refers to a class of linear olefins comprising more than5% of olefins in which the carbon-carbon double bond is not terminal(i.e., the double bond is not located between the first and secondcarbon atoms of the chain).

Partially Branched Linear Olefins—The term “partially branched linearolefins” refers to a class of linear olefins comprising less than onealkyl branch per straight chain containing the double bond, wherein thealkyl branch may be a methyl group or higher. Partially branched linearolefins may also contain double-bond isomerized olefin.

Branched Olefins—The term “branched olefins” refers to a class ofolefins comprising one or more alkyl branches per linear straight chaincontaining the double bond, wherein the alkyl branch may be a methylgroup or higher.

C₁₂-C₃₀ ⁺ Normal Alpha Olefins—This term defines a fraction of normalalpha olefins wherein the carbon numbers below 12 have been removed bydistillation or other fractionation methods.

In one preferred embodiment of the present invention is a process forpreparing an alkylated aromatic compound, wherein said process comprises(a) reacting a first amount of at least one aromatic compound with afirst amount of a mixture of olefins selected from olefins having fromabout 8 to about 100 carbon atoms, in the presence of a strong acidcatalyst; and reacting the product of (a) with an additional amount ofat least one aromatic compound and an additional amount of strong acidcatalyst and, optionally, with an additional amount of a mixture ofolefins selected from olefins having from about 8 to about 100 carbonatoms, wherein the resulting product comprises at least about 85 weightpercent of a 1,2,4 tri-alkylsubstituted aromatic compound.

Aromatic Compound

At least one aromatic compound or a mixture of aromatic compounds may beused for the alkylation reaction in the present invention. Preferablythe at least one aromatic compound or the aromatic compound mixturecomprises at least one of monocyclic aromatics, such as benzene,toluene, xylene, cumene or mixtures thereof. The at least one aromaticcompound or aromatic compound mixture may also comprise bi-cyclic andpoly-cyclic aromatic compounds, such as naphthalenes. More preferably,the at least one aromatic compound or aromatic compound mixture isxylene, including all isomers (i.e., meta-, ortho- and para-), araffinate of xylene isomerization, and mixtures thereof. Mostpreferably, the at least one aromatic compound is ortho-xylene.

Sources of Aromatic Compound

The at least one aromatic compound or the mixture of aromatic compoundsemployed in the present invention is prepared by methods that are wellknown in the art.

Olefins

Sources of Olefins

The olefins employed in this invention may be linear, isomerized linear,branched or partially branched linear. The olefin may be a mixture oflinear olefins, a mixture of isomerized linear olefins, a mixture ofbranched olefins, a mixture of partially branched linear or a mixture ofany of the foregoing.

The olefins may be derived from a variety of sources. Such sourcesinclude the normal alpha olefins, linear alpha olefins, isomerizedlinear alpha olefins, dimerized and oligomerized olefins, and olefinsderived from olefin metathesis. Another source from which the olefinsmay be derived is through cracking of petroleum or Fischer-Tropsch wax.The Fischer-Tropsch wax may be hydrotreated prior to cracking. Othercommercial sources include olefins derived from paraffin dehydrogenationand oligomerization of ethylene and other olefins, methanol-to-olefinprocesses (methanol cracker) and the like.

The olefins may also be substituted with other functional groups, suchas carboxylic acid groups, heteroatoms, and the like, provided that suchgroups do not react with the strong acid catalyst.

The mixture of olefins is selected from olefins with carbon numbersranging from about 8 carbon atoms to about 100 carbon atoms. Preferably,the mixture of olefins is selected from olefins with carbon numbersranging from about 10 to about 80 carbon atoms, more preferred fromabout 14 to about 60 carbon atoms.

In another embodiment, preferably, the mixture of olefins is selectedfrom linear alpha olefins or isomerized olefins containing from about 8to about 100 carbon atoms. More preferably, the mixture of olefins isselected from linear alpha olefins or isomerized olefins containing fromabout 10 to about 80 carbon atoms. Most preferably, the mixture ofolefins is selected from linear alpha olefins or isomerized olefinscontaining from about 14 to about 60 carbon atoms.

Furthermore, in a preferred embodiment, the mixture of olefins containsa distribution of carbon atoms that comprise from about 40 to about 90percent C₁₂ to C₂₀ and from about 4 percent to about 15 percent C₃₂ toC₅₈. More preferably, the distribution of carbon atoms comprises fromabout 50 to about 80 percent C₁₂ to C₂₀ and from about 4 percent toabout 15 percent C₃₂ to C₅₈.

The mixture of branched olefins is preferably selected from polyolefinswhich may be derived from C₃ or higher monoolefins (i.e., propyleneoligomers, butylenes oligomers, or co-oligomers etc.). Preferably, themixture of branched olefins is either propylene oligomers or butylenesoligomers or mixtures thereof.

Normal Alpha Olefins

Preferably, the mixture of linear olefins that may be used for thealkylation reaction is a mixture of normal alpha olefins selected fromolefins having from about 8 to about 100 carbon atoms per molecule. Morepreferably the normal alpha olefin mixture is selected from olefinshaving from about 10 to about 80 carbon atoms per molecule. Mostpreferably, the normal alpha olefin mixture is selected from olefinshaving from about 12 to about 60 carbon atoms per molecule. Anespecially preferred range is from about 14 to about 60.

In one embodiment of the present invention, the normal alpha olefins areisomerized using at least one of two types of acidic catalysts, solid orliquid. A solid catalyst preferably has at least one metal oxide and anaverage pore size of less than 5.5 angstroms. More preferably, the solidcatalyst is a molecular sieve with a one-dimensional pore system, suchas SM-3, MAPO-11, SAPO-11, SSZ-32, ZSM-23, MAPO-39, SAPO-39, ZSM-22 orSSZ-20. Other possible acidic solid catalysts useful for isomerizationinclude ZSM-35, SUZ-4, NU-23, NU-87 and natural or syntheticferrierites. These molecular sieves are well known in the art and arediscussed in Rosemarie Szostak's Handbook of Molecular Sieves (New York,Van Nostrand Reinhold, 1992) which is herein incorporated by referencefor all purposes. A liquid type of isomerization catalyst that can beused is iron pentacarbonyl (Fe(CO)₅).

The process for isomerization of normal alpha olefins may be carried outin batch or continuous mode. The process temperatures may range fromabout 50° C. to about 250° C. In the batch mode, a typical method usedis a stirred autoclave or glass flask, which may be heated to thedesired reaction temperature. A continuous process is most efficientlycarried out in a fixed bed process. Space rates in a fixed bed processcan range from 0.1 to 10 or more weight hourly space velocity.

In a fixed bed process, the isomerization catalyst is charged to thereactor and activated or dried at a temperature of at least 150° C.under vacuum or flowing inert, dry gas. After activation, thetemperature of the isomerization catalyst is adjusted to the desiredreaction temperature and a flow of the olefin is introduced into thereactor. The reactor effluent containing the partially-branched,isomerized olefins is collected. The resulting partially-branched,isomerized olefins contain a different olefin distribution (i.e., alphaolefin, beta olefin; internal olefin, tri-substituted olefin, andvinylidene olefin) and branching content that the unisomerized olefinand conditions are selected in order to obtain the desired olefindistribution and the degree of branching.

Acid Catalyst

Typically, the alkylated aromatic compound may be prepared using strongacid catalysts (Bronsted or Lewis acids). The term “strong acid” refersto an acid having a pK_(a) of less than about 4. The term “strong acid”is also meant to include mineral acids stronger than hydrochloric acidand organic acids having a Hammett acidity value of at least minus 10 orlower, preferably at least minus 12 or lower, under the same conditionsemployed in context with the herein described invention. The Hammettacidity function is defined as:H _(o) =pK _(BH+)−log(BH ⁺ /B)where B is the base and BH⁺ its protonated form, pK_(BH+) is thedissociation constant of the conjugate acid and BH⁺/B is the ionizationratio; lower negative values of H_(o) correspond to greater acidstrength.

Preferably, the strong acid catalyst is selected from a group consistingof hydrochloric acid, hydrofluoric acid, hydrobromic acid, sulfuricacid, perchloric acid, trifluoromethane sulfonic acid, fluorosulfonicacid, and nitric acid. Most preferred, the strong acid catalyst ishydrofluoric acid.

The alkylation process may be carried out in a batch or continuousprocess. The strong acid catalyst may be recycled when used in acontinuous process. The strong acid catalyst may be recycled orregenerated when used in a batch process or a continuous process.

The strong acid catalyst may be regenerated after it becomes deactivated(i.e., the catalyst has lost all or some portion of its catalyticactivity). Methods that are well known in the art may be used toregenerate the deactivated hydrofluoric acid catalyst.

Process for Preparing Alkylated Aromatic Compound

In one embodiment of the present invention, the alkylation process iscarried out by reacting a first amount of at least one aromatic compoundor a mixture of aromatic compounds with a first amount of a mixture ofolefin compounds in the presence of a strong acid catalyst, such ashydrofluoric acid, in a first reactor in which agitation is maintained,thereby producing a first reaction mixture. The resulting first reactionmixture is held in a first alkylation zone under alkylation conditionsfor a time sufficient to convert the olefin to aromatic alkylate (i.e.,a first reaction product). After a desired time, the first reactionproduct is removed from the alkylation zone and fed to a second reactorwherein the first reaction product is reacted with an additional amountof at least one aromatic compound or a mixture of aromatic compounds andan additional amount of strong acid catalyst and, optionally, with anadditional amount of a mixture of olefin compounds, wherein agitation ismaintained. A second reaction mixture results and is held in a secondalkylation zone under alkylation conditions for a time sufficient toconvert the olefin to aromatic alkylate (i.e., a second reactionproduct). The second reaction product is fed to a liquid-liquidseparator to allow hydrocarbon (i.e., organic) products to separate fromthe strong acid catalyst. The strong acid catalyst may be recycled tothe reactor(s) in a closed loop cycle. The hydrocarbon product isfurther treated to remove excess un-reacted aromatic compounds and,optionally, olefinic compounds from the desired alkylate product. Theexcess aromatic compounds may also be recycled to the reactor(s).

In another embodiment of the present invention, the reaction takes placein more than two reactors which are located in series. Instead offeeding the second reaction product to a liquid-liquid separator, thesecond reaction product is fed to a third reactor wherein the secondreaction product is reacted with an additional amount of at least onearomatic compound or a mixture of aromatic compounds and an additionalamount of strong acid catalyst and, optionally, with an additionalamount of a mixture of olefin compounds, wherein agitation ismaintained. A third reaction mixture results and is held in a thirdalkylation zone under alkylation conditions for a time sufficient toconvert the olefin to aromatic alkylate (i.e., a third reactionproduct). The reactions take place in as many reactors as necessary toobtain the desired alkylated aromatic reaction product.

The total charge mole ratio of hydrofluoric acid to the mixture ofolefin compounds is about 1.0 to 1 for the combined reactors.Preferably, the charge mole ratio of hydrofluoric acid to the mixture ofolefin compounds is no more than about 0.7 to 1 in the first reactor andno less than about 0.3 to 1 in the second reactor.

The total charge mole ratio of the aromatic compound to the mixture ofolefin compounds is about 7.5 to 1 for the combined reactors.Preferably, the charge mole ratio of the aromatic compound to themixture of olefin compounds is no less than about 1.4 to 1 in the firstreactor and is no more than about 6.1 to 1 in the second reactor.

Many types of reactor configurations may be used for the reactor zone.These include, but are not limited to, batch and continuous stirred tankreactors, reactor riser configurations, ebulating bed reactors, andother reactor configurations that are well known in the art. Many suchreactors are known to those skilled in the art and are suitable for thealkylation reaction. Agitation is critical for the alkylation reactionand can be provided by rotating impellers, with or without baffles,static mixers, kinetic mixing in risers, or any other agitation devicesthat are well known in the art.

The alkylation process may be carried out at temperatures from about 0°C. to about 100° C. The process is carried out under sufficient pressurethat a substantial portion of the feed components remain in the liquidphase. Typically, a pressure of 0 to 150 psig is satisfactory tomaintain feed and products in the liquid phase.

The residence time in the reactor is a time that is sufficient toconvert a substantial portion of the olefin to alkylate product. Thetime required is from about 30 seconds to about 30 minutes. A moreprecise residence time may be determined by those skilled in the artusing batch stirred tank reactors to measure the kinetics of thealkylation process.

The at least one aromatic compound or mixture of aromatic compounds andthe mixture of olefins may be injected separately into the reaction zoneor may be mixed prior to injection. Both single and multiple reactionzones may be used with the injection of the aromatic compounds and themixture of olefins into one, several, or all reaction zones. Thereaction zones need not be maintained at the same process conditions.

The hydrocarbon feed for the alkylation process may comprise a mixtureof aromatic compounds and a mixture olefins in which the molar ratio ofaromatic compounds to olefins is from about 0.5:1 to about 50:1 or more.In the case where the molar ratio of aromatic compounds to olefinis >1.0 to 1, there is an excess amount of aromatic compounds present.Preferably an excess of aromatic compounds is used to increase reactionrate and improve product selectivity. When excess aromatic compounds areused, the excess un-reacted aromatic in the reactor effluent can beseparated, e.g. by distillation, and recycled to the reactor.

Tri-Alkylsubstituted Alkylated Aromatic Compound

The product of the presently claimed invention is a tri-alkylsubstitutedalkylated aromatic compound. Preferably, the resulting product comprisesat least about 80 weight percent of a 1,2,4 tri-alkylsubstitutedaromatic compound. More preferred, the resulting product comprises atleast about 85 weight percent, even more preferred at least about 90weight percent of a 1,2,4 tri-alkylsubstituted aromatic compound.

Other embodiments will be obvious to those skilled in the art.

The following examples are presented to illustrate specific embodimentsof this invention and are not to be construed in any way as limiting thescope of the invention.

EXAMPLES Examples 1-3

Alkylation of Ortho-Xylene with C₁₄₋₃₀₊ NAO Using Two AlkylationReactors in Series

The alkylated ortho-xylenes of Examples 1-3 were prepared in acontinuous alkylation pilot plant using hydrofluoric acid (HF) in whichtwo alkylation reactors (1.15 liter volume each) were in series followedby a 25 liter settler to separate the organic phase from the HF phase.All equipment was maintained under a pressure of 5 bar and the reactorsand settler were jacketed to allow temperature control. In addition, thealkylation reactors were configured such that the ortho-xylene, normalalpha olefins (NAO) and HF could be fed to each reactor at a specifiedrate. Following the settler, the organic phase was removed through avalve and allowed to expand to atmospheric pressure. The HF acid phasewas separated and neutralized with caustic. The resulting organic phasewas then distilled under vacuum to remove the excess ortho-xylene.

The alkylation feedstock consisted of a mixture of o-xylene and C₁₄-C₃₀⁺ normal alpha olefins with a molar ratio of xylene/olefin=7.5. Theolefin used to make this feed was a blend of commercial C₁₄-C₃₀₊ cuts.The distribution of olefins in the feed is shown in Table A.

TABLE A Olefin Feedstock Distribution Carbon Number Wt-% 14 24.4 16 18.418 15.2 20 9.7 22 8.2 24 5.7 26 5.4 28 5.0   30+ 8.0

The feed mixture was stored under dry nitrogen during use. Because ofthe waxy nature of the alpha olefin, the alkylation feed mixture washeated to 50° C. to keep all the olefin in solution. O-Xylene was alsostored under dry nitrogen during use.

Table 1 summarizes the HF alkylation conditions for Examples 1-3 and thearomatic alkylates' chemical properties.

Example 4

Infrared Method to Determine Relative Percentage of 1,2,3 Alkyl and1,2,4-Alkyl Aromatic Ring Attachment

The infrared spectrum of a sample of alkylated ortho-xylene product wasobtained using an infrared spectrometer (Thermo model 4700) equippedwith a rebounce diamond attenuated reflectance cell. The absorbancespectrum of the sample between 600 and 1000 cm⁻¹ was displayed and thepeaks at about 780, 820, and 880 cm⁻¹ were integrated. The relativepercentage area of each peak was calculated and the percent 1,2,3-alkylaromatic content is represented by the relative area percentage of the780 cm⁻¹ peak.

Example 5

Carbon Nuclear Magnetic Resonance Method to Determine the Percent AlkylAttachment Position to the Aromatic Ring

Quantitative ¹³C NMR spectra were obtained on a 300 MHz Varian GeminiNMR (75 MHz carbon) using about 1.0 g of sample dissolved in about 3.0mL of 0.5 M chromium (acac)₃ in chloroform-d contained in a 10 mm NMRtube. The transmitter pulse sequence (delay (2.2 s), 90 pulseacquisition (0.853 s) was employed with the decoupler (WALTZ-16) gatedoff during the delay and on during acquisition. Cursory examination ofthe T1's for the quaternary carbons at our CR(acac)₃ levels indicatedthey were about 0.4-0.5 s. Thus, the relaxation delay was always morethan four times the longest T1. We believe this is sufficient to allowresidual NOE to die away between pulse excitations even though thedecoupler duty cycle is above the recommended 5-10% range forquantitative experiments. Integration of the ¹³C NMR spectrum wascarried out with no base-line correction.

The integrated peak intensity for the quarternary carbons (Q) on thearomatic ring carbons substituted with the long chaing alkyl group andthe methane (benzylic) carbons (M) of the long chain alkyl groups wherethe long chain alkyl group is attached to the aromatic ring are used tocalculate the percent alkyl attachment position. For the different alkylchain attachments, the following assignments were made (in ppm downfieldfrom TMS): 2-position (R=Methyl); Q=145.475 ppm, M=39.56 ppm; 3-position(R=Ethyl), Q=143.502 ppm, M=47.50 ppm; 4-position (R=n-Propyl), Q=143.86ppm, M=45.4 ppm; 5-position and higher (R=greater than n-Propyl),Q=143.86, M=45.69 ppm. The NMR spectrum is integrated and the signalsbetween 143 to 147 ppm, and 39 to 48 ppm are enlarged and integrated.For the 143 to 147 ppm region integral, the relative amount of R=Methyl,R=Ethyl and R=n-Propyl were determined. For the 39-48 ppm regionintegral, one obtains the relative amounts of R=Methyl, R=Ethyl,R=n-Propyl and R>n-Propyl. To perform the calculations, first, check tosee that the integrals for each aromatic carbon is the same. Sum theintegrals for each of the Q and M peaks and calculate the percentageattachment from both the aromatic quartemary (Q) and aliphatic methine(M) integrals of the assigned peaks. For example, the amount of2-attachment from the integration of the aromatic quaternary carbonswould equal the integral for the 145.475 ppm signal divided by the totalof the integrals for the 145.475 ppm peak plus the integral for the143.502 ppm peak plus the integral for the 143.86 ppm peak. Thealiphatic methine carbons provide the 2-, 3-, 4-, and >4-alkylattachment while the aromatic quaternary carbons provide only the 2-,3-, and 4-alkyl attachment values. The attachment values determined bythe aliphatic methine and the aromatic quaternary carbons agreereasonably well.

TABLE I HF Alkylation of ortho-xylene with _(C14-30+) NAO Using TwoIn-series Alkylation Reactors (R1 and R2) Reactor Total Tem- Reactorper- Relative % Relative % % Alkyl Chain Residence Ortho-Xylene/NAOature Aromatic Ring Aromatic Ring Attachment* Time HF/NAO CMR CMR ° C.Attachment Attachment 2-Aryl 3-Aryl 4-Aryl 4+ Example (minutes) R1 R2Overall R1 R2 Overall R1 R2 % 1,2,3- % 1,2,4- Alkane Alkane AlkaneArylAlkane 1 17 0.7 0.3 1.0 1.4 6.1 7.5 64 60 11.0 89.0 11 10 15.6 63.42 25 0.7 0.3 1.0 1.4 6.1 7.5 70 60 13.0 87.0 12.4 10.7 16.0 60.9 3 170.7 0.3 1.0 1.4 6.1 7.5 70 60 10.0 90.0 11.2 11.1 15.5 62.2 *% AlkylChain Attachment refers to the carbon number along the alkyl chain towhich the aromatic ring is attached.

1. A process for alkylating an aromatic compound comprising (a) reactinga first amount of at least one aromatic compound with an amount of amixture of olefins selected from olefins having from about 8 to about100 carbon atoms, in the presence of a strong acid catalyst; and (b)reacting the product of (a) with an additional amount of at least onearomatic compound and an additional amount of a strong acid catalystand, optionally, with an additional amount of a mixture of olefinsselected from olefins having from about 8 to about 100 carbon atoms,wherein the resulting product comprises at least about 80 weight percentof a 1,2,4 tri-alkylsubstituted aromatic compound.
 2. The processaccording to claim 1 wherein the product of (b) further comprises 1,2,3,tri-alkylsubstituted aromatic compound or mixtures thereof.
 3. Theprocess according to claim 1 wherein the at least one aromatic compoundis selected from unsubstituted aromatic compounds, monosubstitutedaromatic compounds, and disubstituted aromatic compounds.
 4. The processaccording to claim 3 wherein the at least one aromatic compound isselected from benzene, toluene, meta-xylene, para-xylene, ortho-xylene,and mixtures thereof.
 5. The process according to claim 4 wherein the atleast one aromatic compound is selected from meta-xylene, para-xylene,ortho-xylene and mixtures thereof.
 6. The process according to claim 5wherein the at least one aromatic compound is ortho-xylene.
 7. Theprocess according to claim 1 wherein the mixture of olefins in step (a)or step (b) is a mixture of linear olefins, a mixture of linearisomerized olefins, a mixture of branched olefins, a mixture ofpartially branched olefins, or a mixture thereof.
 8. The processaccording to claim 7 wherein the mixture of olefins in step (a) or step(b) is a mixture of linear olefins.
 9. The process according to claim 8wherein the mixture of linear olefins is a mixture of normal alphaolefins.
 10. The process according to claim 9 wherein the mixture oflinear olefins comprises olefins derived through cracking of petroleumwax or Fischer Tropsch wax.
 11. The process according to claim 10wherein the Fischer Tropsch wax is hydrotreated before cracking.
 12. Theprocess according to claim 7 wherein the mixture of olefins comprisesfrom about 8 carbon atoms to about 100 carbon atoms.
 13. The processaccording to claim 12 wherein the mixture of olefins is derived fromlinear alpha olefins or isomerized olefins containing from about 8 to100 carbon atoms.
 14. The process according to claim 13 wherein themixture of olefins is derived from linear alpha olefins or isomerizedolefins containing from about 10 to about 80 carbon atoms.
 15. Theprocess according to claim 14 wherein the mixture of olefins is derivedfrom linear alpha olefins or an isomerized olefins containing from about14 to about 60 carbon atoms.
 16. The process according to claim 8wherein the mixture of linear olefins is a mixture of linear internalolefins which have been derived from olefin metathesis.
 17. The processaccording to claim 1 wherein the mixture of olefins is a mixture ofbranched olefins.
 18. The process according to claim 17 wherein themixture of branched olefins comprises polyolefin compounds derived fromC₃ or higher monoolefins.
 19. The process according to claim 18 whereinthe polyolefin compound is either polypropylene or polybutylene.
 20. Theprocess according to claim 19 wherein the polyolefin compound ispolypropylene.
 21. The process according to claim 20 wherein thepolyolefin compound is polybutylene.
 22. The process according to claim1 wherein the strong acid catalyst is selected from the group consistingof hydrochloric acid, hydrofluoric acid, hydrobromic acid, sulfuricacid, perchloric acid, trifluoromethanesulfonic acid, fluorosulfonicacid, and nitric acid.
 23. The process according to claim 22 wherein thestrong acid catalyst is hydrofluoric acid.
 24. The process according toclaim 1 wherein the strong acid catalyst may be recycled.
 25. Theprocess according to claim 1 wherein the reaction takes place in acontinuous process.
 26. The process according to claim 1 wherein, instep (b), the product of step (a) is reacted with an additional amountof at least one aromatic compound and an additional amount of a mixtureof olefins selected from olefins having from about 8 to about 100 carbonatoms.
 27. The process according to claim 1 wherein the resultingproduct comprises at least about 85 weight percent of a 1,2,4tri-alkylsubstituted aromatic compound.